#include <stdio.h>

int main()
{
    float cel, fahr;
    int lower, upper, step;
    char sel;

    lower=0, upper=300, step=10;
    
    printf("Please choose one:\nA. Fahr to Cel.\nB. Cel to fahr.\nYOUR ANSWER: ");

    scanf("%c", &sel);

    if(sel==65||sel==97)
        for(fahr=upper;fahr>=lower;fahr=fahr-step)
        {
            cel=5.0*(fahr-32)/9.0;
            printf("%6.1f\t%6.1f\n",fahr,cel);
        }
    else if(sel==66||sel==98)
        for(cel=upper;cel>=lower;cel=cel-step)
        {
            fahr=9.0*cel/5.0+32;
            printf("%6.1f\t%6.1f\n",cel,fahr);
        }
    else
        printf("Sorry, your input is wrong!\n");

    return 0;
}